Why is the level of atmospheric CO2 chaining records despite the pandemic?

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The atmospheric concentration of carbon dioxide (CO2) continues to chain records, perpetuating an unfortunate tradition. Also, the latest measurements indicate that this gas now has a level 50% higher than that before the industrial revolution. Values ​​that take us back almost 4 million years in the past, at a time when the global climate was much warmer.

The reduction in greenhouse gas emissions (GHG) due to the Covid-19 pandemic will have been only a slight interlude to a general increase. While the articulation of an economic recovery suggests a significant rebound in emissions, observations show that the level of CO2 broke a new record in 2020. Indeed, although we then filled the atmospheric reservoir at a slower rate, we continued to fill it anyway. The pandemic simply brought us back to the emission rate that was that of 2011-2012.

CO2 emissions per year (in billions of tonnes) related to fossil fuels. Also, note the value expected for 2020 and which bears the mark – unprecedented but limited – of the pandemic. Credits: Global Carbon Project.

CO2 : from one recording to another

The last measurements carried out at the historic observatory of Long Mountain (Hawaii) report an atmospheric concentration of CO2 of 417.14 ppm (parts per million) for March 2021. A value 50% higher than that of the pre-industrial period and independently confirmed by the NOAA. On April 3, the latter even reported an unprecedented daily peak of 421.21 ppm.

For 2020, the observatory reports an annual average of CO2 at 413.94 ppm. This is 2.51 ppm higher than in 2019 – the NOAA giving the figure of 2.58 ppm. An increment very well anticipated by the forecasts of the Met Office published each beginning of the year. In January 2020, the researchers thus announced an increase of 2.74 ± 0.57 ppm. However, the unexpected appearance of the pandemic made it necessary to revise these estimates and it is therefore an increment of 2.48 ± 0.57 ppm that was ultimately predicted. The agreement between calculated and observed values ​​is undeniable. This perpetuates a chain of record values ​​that has become sadly usual.

The value forecast for 2021 (417 ppm) is 50% higher than that of the pre-industrial period (278 ppm). Credits: Met Office.

“The observed increase in CO2 was therefore closer to the central estimate of the revised forecast taking into account the emission reductions. than the initial forecast “, reports the Met Office in a communicated. “However, the difference between the two forecasts was smaller than the uncertainty margin [± 0,57 ppm] and that the variability from one year to another (…). This shows that the reduction in emissions in 2020 was not sufficient to have a substantial impact on the accumulation of CO2 in the atmosphere and that much greater emission reductions and in the longer term will be necessary to slow down or stop the rise ”.

Lessons from the Covid-19 pandemic

The current year sees a clear recovery in economic activity and associated greenhouse gas emissions. For 2021, the Met Office projections anticipate an average concentration in CO2 of 416.3 ± 0.6 ppm at Mauna Loa – a reference observatory representative of the world average. In other words, we expect a slightly lower increment than in 2020. The cause? The presence of the phenomenon The girl in the equatorial Pacific which tends to temporarily strengthen the absorption of CO2 by vegetation. Quite the opposite of the phenomenon The boy.

In summary, while the pandemic has not had a strong influence as such on emissions of GHG, it nevertheless testifies to the following. It is not by living as little as possible that we will solve the climate problem. Emissions reduction needs requiring less individual actions than a structural, deep and collective reshuffle of our economy. As such, it should be remembered that more than 70% of GHG are piloted by one hundred companies only. A challenge commensurate with the challenges facing us when the planet has already gained 1 ° C since the start of the industrial revolution.

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